There was some grumbling among Wikileak fans this week that the site was not showing up in Twitter's Trends feed. Twitter responded with an explanation as to why this was so - no, it was not censorship - that also provides some insight into how, or how difficult, it can be for any one brand or topic to make it into the Trend feed.

Twitter Trends are automatically generated by an algorithm that attempts to identify topics about which discussion has suddenly picked up. It is designed, in short, to identify the most breaking of breaking news around the world in real-time. "The Trends list captures the hottest emerging topics, not just what's most popular," Twitter said. "Put another way, Twitter favors novelty over popularity."

This is roughly how the process works: of the more than 95 million Tweets sent every day, Twitter breaks the topics of these Tweets into Trends when the volume of Tweets about the topic dramatically increases at any given moment. Sometimes a topic doesn't break into the Trends list because its popularity isn't as widespread as people believe, Twitter said. "And, sometimes, popular terms don't make the Trends list because the velocity of conversation isn't increasing quickly enough, relative to the baseline level of conversation happening on an average day." This, it concluded, is what happened with #wikileaks - and probably your campaign too.